The US just had its hottest summer on record

Key Points:

• The United States experienced its hottest summer on record in 132 years, surpassing the previous records set in 1936 and 2021, with August 2026 and the June-August period both setting all-time temperature highs.
• Widespread above-average temperatures affected nearly all of the Lower 48 states, driven by powerful heat domes, with August averaging 75.6°F, 3.5°F above the 20th-century average, and the summer average reaching 74.4°F, 3°F above normal.
• The Southwest saw particularly intense heat, with Arizona, New Mexico, Utah, and Colorado setting record warm summers, worsening the ongoing Colorado River water crisis.
• A stark imbalance was observed in temperature records, with 1,541 monthly record highs compared to only 87 record lows, highlighting the impact of rapid climate warming.
• The record heat is attributed to a combination of a strengthening El Niño and long-term human-caused climate change, which is driving more frequent and severe heat waves; US summer temperatures have increased by about 0.46°F per decade since 1970.